1. Field
The invention relates to a device for locking the steering shaft of a motor vehicle against rotation by means of a locking bolt that cooperates with locking recesses of the steering shaft and which, with the aid of a control member that can be rotated back and forth, is displaceable back and forth, radially relative to the axis of rotation of the control member between a locking position and a release position, and which with a laterally protruding pin engages a spiral groove of the control member that winds around the axis of rotation of the control member on the end face of the control member adjacent to the locking bolt.
2. Related Art
Such a device for locking the steering shaft of a motor vehicle so that it can no longer be rotated is known. In the known device, the locking bolt is made in two parts and is provided with a helical compression spring, against the action of which the locking bolt part cooperating with the locking recesses of the steering shaft and the locking bolt part cooperating with the control member can be pushed together when the control member is rotated into the position corresponding to the locking position of the locking bolt, but the locking bolt part that cooperates with the steering shaft cannot enter into any locking recess of the steering shaft, since the steering shaft is not in a rotary position where one of its locking recesses is aligned with this locking bolt part. The pin provided on the other locking bolt part and engaging the spiral groove of the control member constitutes an immovable lateral protrusion of this locking bolt part. The control member is made as a circular disk which can be rotated back and forth with the aid of a locking cylinder. This two-part design of the locking bolt with a helical compression spring is relatively complex and susceptible to malfunction (German Patent 506 781).
In another similar known device for locking the steering shaft of a motor vehicle against rotation, a one-piece locking bolt is provided whose laterally protruding pin is solidly joined to the locking bolt and which extends through a spiral slot in a circular control disk that can be rotated back and forth by means of a locking cylinder. The control disk can be rotated into the position corresponding to the locking position of the locking bolt only when a locking recess of the steering shaft is aligned with the locking bolt, and the locking bolt can enter the locking recess in order to assume its locking position (U.S. Pat. No. 1,786,186).